Their move north to London from nesting sites on the south coast could be a sign of climate change, experts believe...
Many people had been astonished that the bird, more commonly seen in the Mediterranean, was now breeding in this country.
Warmer winters "will certainly have benefited" its spread, he said.
Thames Water's biodiversity manager Andy Tomczynski said: "We are delighted that these rare and beautiful birds have chosen to breed in the capital and we hope they can go on and establish a permanent colony at our Walthamstow reservoirs.
"Little Egrets do not cope well with harsh winters and only started breeding in the UK a decade ago, colonising parts of the south coast. Their nesting further to the north could be another sign of climate change."
Tags: Birds, Climate Change, Global Warming